The proposed investigations will attempt to define the role of ribonucleoprotein (RNP) complexes in the processing of non-ribosomal RNA in the nuclei of higher cells, and in the transfer of messenger RNA into active polyribosomes. The kinetics of synthesis and turnover of the various protein components and RNA sequences of 30S nuclear RNP of mouse ascites cells will be determined. The components of the complexes isolated from various normal and neoplastic tissues will be compared, and the effects of altered metabolic states determined.